A measuring device for measuring an elevator shaft has two cable-like, elongate guide elements that extend in parallel with one another, a measuring platform and a lifting apparatus. Each of the guide elements is fixedly attached to an upper holding point and a lower holding point in the elevator shaft and is tensioned between the upper holding point and the lower holding point. The measuring platform has guide apparatuses that laterally support the measuring platform on the guide elements and guide the measuring platform parallel to the guide elements during a displacement movement in a displacement direction. The measuring platform has a distance measuring apparatus to measure lateral distances to the lateral walls of the elevator shaft. The lifting apparatus moves the measuring platform in the displacement direction.